Laura Robson is having the tournament of her life in New York - even if Wayne Rooney cannot spell her name.

The 18-year-old made it back-to-back wins over former grand slam champions today when she added Li Na's scalp to that of Kim Clijsters with another stunning performance at the US Open.

If Wednesday's victory over the three-time champion, which sent Clijsters into retirement, was a coming of age for Robson, this was even better.

Li has been one of the form players of the north American summer but in the end she was outplayed by the world number 89, who powered to a 6-4 6-7 (5/7) 6-2 victory.

Robson's performances have attracted a lot of attention, and Rooney tweeted how impressed he was by the teenager as he watched on television, although rather spoiled it by calling her Laura Robinson, which he later blamed on his phone.

Robson said smiling: "He called me Robinson. I saw that when I was stretching. He blamed it on predictive text. Can you blame that on predictive text, though? I'm not so sure."

Comedian James Corden was in the crowd on Louis Armstrong Stadium, and Robson hopes her success can help boost the profile of tennis.

She added: "It's great that he (Rooney) watched, even though he got my name wrong. The more people that watch, the better. Maybe a few people a bit younger than me have seen his tweets and said, 'I want to play a bit of tennis now.'

"It's great, and I think James Corden was watching me today as well. I spotted him midway through the first set, and then spent the rest of the time trying not to wave."

The first set was rather error-strewn from both players, but ninth seed Li in particular, and, after Robson had been broken serving for it when she double-faulted, Li promptly dropped her serve again.

The Chinese player won the French Open last year and showed her class at the end of a tight second set, proving just too strong in the tie-break.

It looked like Li may have dodged a bullet but instead Robson redoubled her efforts and her prodigious ball striking ultimately proved too much for her opponent.

The 18-year-old threatened a break in the third game of the decider and then made her move two games later despite an unlucky line call.

There was no stopping Robson now and she broke for a second consecutive time before making it five games in a row to clinch victory and set up a date with yet another grand slam champion, last year's US Open winner Sam Stosur.

Robson's belief did not waver despite losing the second set, and she said: "I had the opportunity to win it in two. It was a really close tie-break, and at 5-5 she played two really good points. There's not much that I can do off that.

"I knew that if I kept playing the way that I was and kept playing how I started the first set, really aggressive and accelerating on my forehand when I had the opportunity, then I knew that she would struggle.

"That's what I did. I also think that I returned a bit more aggressively in the third set."

Robson has come close to big wins before, particularly in two meetings with Maria Sharapova, one at Wimbledon last year and the other at the Olympics a month ago.

The teenager said: "I have just worked hard over the last few weeks and I feel like I'm playing very good. I have had lots of tough matches against some very experienced opponents so, the way that I see it, it was time to start winning a few of them."

That Robson secured the win despite being on the wrong end of a couple of dubious umpiring calls, and did not let them affect her, was even more impressive.

The first incident came on break point in the fifth game of the third set when she hit a shot that landed on the baseline and Li could barely get a racquet to.

It was called out and, although Robson's challenge was correct, she was made to replay the point and Li won it.

The same thing happened in the next game when a Robson serve was erroneously called out and again they replayed it, despite the British player's protestations.

Robson said: "I wouldn't say I wasn't distracted. I was a little bit annoyed. But that's what happens from time to time, so you've got to deal with it.

"I think being a little bit annoyed seemed to help me, seeing as I broke the first game and then I held serve the next time it happened. It won't be the last time."